The instant invention relates generally to methods and apparatus for turning flat articles and is particularly related to methods and apparatus for turning envelopes.
Turning devices for flat articles that are conveyed horizontally are required in mail processing machines. Examples of flat articles include envelopes, letters, postcards, endless forms issued by a computer controlled printing device that are cut into sheets from an endless web, and the like. In an inserter and mail processing machine, sheets are fed, one by one or collected together, to a folding station and subsequently, with or without additional enclosures, are conveyed to an inserting station where the sheets are inserted into an envelope.
After insertion of the sheets into the envelope, the stuffed envelope is forwarded to a postage station where postage is imprinted thereon by a postage meter. In certain inserters, it is necessary to turn the stuffed envelopes through a 90 degree angle if the postage meter is oriented in the same direction as the discharge from the inserting station. Many types of turners are known in the prior art to effect a 90 degree turn. Many, however, turn the envelope on an edge which risks damage to the envelope and is more time consuming because a greater radius of turn is required than for a turn on the center of gravity of the envelope. In general, the prior art devices slow down the throughput of the mailing system. The instant invention therefore provides a method and apparatus for turning flat articles such as envelopes on their centers of gravity through 90 degrees and removes them from the turning mechanism more quickly and efficiently than prior art devices.